If a plaintiff lies in a complaint, you have a sequence of tools to fight back: deny each false allegation in your Answer, ask the court to dismiss the case, seek sanctions against the plaintiff or their attorney for a baseless filing, use discovery to expose the contradictions, move for summary judgment when the evidence doesn’t support the claims, and in some cases countersue for malicious prosecution or abuse of process. If the plaintiff repeats the lies under oath, criminal perjury exposure also comes into play. The common thread is that each stage of the case gives you another chance to force the plaintiff to back up what they wrote, and each chance has its own deadline.
Deny the False Allegations in Your Answer
The first move is filing an Answer. In federal court you generally have 21 days after being served to file one.1Legal Information Institute. Federal Rules of Civil Procedure Rule 12 – Defenses and Objections State deadlines usually fall between 20 and 30 days. Miss it and the court can enter a default judgment, which means the plaintiff wins automatically, lies included.
In the Answer you respond to each numbered paragraph of the complaint one of three ways: admit, deny, or state that you lack enough information to respond, which the court treats as a denial. A denial forces the plaintiff to prove the allegation at trial. Anything you fail to address counts as admitted, so working through the complaint line by line matters.2Legal Information Institute. Federal Rules of Civil Procedure Rule 8 – General Rules of Pleading
The Answer is also where you raise affirmative defenses, which are legal reasons you should win even if some of the plaintiff’s factual claims turn out to be true. Statute of limitations and the plaintiff’s own fault are common examples. Raise them in the Answer or you can lose the right to argue them later.
Move to Dismiss the Case Before It Goes Further
Instead of answering paragraph by paragraph, you can ask the court to throw the case out at the start. A Motion to Dismiss is filed before the Answer and argues that the complaint has a fatal legal defect.1Legal Information Institute. Federal Rules of Civil Procedure Rule 12 – Defenses and Objections The most common version, a 12(b)(6) motion, argues that even if everything the plaintiff wrote were true, it still wouldn’t add up to a valid legal claim.
Other grounds include the court lacking jurisdiction over you or the subject matter, the plaintiff suing in the wrong location, and defective service. Important to understand: this is a legal challenge, not a factual one. The judge won’t weigh whether the allegations are true at this stage, so a motion to dismiss isn’t the place to prove the plaintiff is lying. If the motion fails, you still need to file your Answer.
Ask the Court to Sanction a Frivolous Filing
Every attorney or self-represented party who signs a court filing is certifying, under Federal Rule of Civil Procedure 11, that the factual claims have evidentiary support (or likely will after reasonable investigation), that the legal arguments aren’t frivolous, and that the filing isn’t being used to harass or to drive up the other side’s costs.3Legal Information Institute. Federal Rules of Civil Procedure Rule 11 – Signing Pleadings, Motions, and Other Papers; Representations to the Court; Sanctions State courts have their own versions of the same rule.
If a complaint is packed with fabricated facts, you can file a motion asking the judge to sanction the plaintiff, their lawyer, or both. There’s a mandatory cooling-off step: you have to serve the motion on the other side first and give them 21 days to withdraw or fix the problematic filing before you can bring it to the judge. That safe harbor means sanctions are aimed at parties who double down after being called out.
Sanctions can include a monetary penalty payable to the court, an order reimbursing your reasonable attorney’s fees, or non-monetary measures like required training or restrictions on future filings. Judges don’t hand them out lightly. You have to show the false statements were significant and that the filing violated Rule 11’s standards. Being wrong about some facts isn’t the same as lying, and the court will draw that line carefully.
Expose the Lies in Discovery
If the case survives the pleadings stage, both sides enter discovery, where you gather the evidence to show the complaint doesn’t hold up. False complaints often collapse here because the plaintiff finally has to produce documents and give sworn testimony.
You have three main tools. Interrogatories are written questions the plaintiff must answer under oath; federal courts cap these at 25 per party unless the court allows more.4Legal Information Institute. Federal Rules of Civil Procedure Rule 33 – Interrogatories to Parties Requests for production are formal demands for documents, electronic files, photographs, and other tangible evidence in the plaintiff’s possession.5Legal Information Institute. Federal Rules of Civil Procedure Rule 34 – Producing Documents, Electronically Stored Information, and Tangible Things Depositions are live, recorded sessions where the plaintiff answers questions under oath; federal rules generally limit each witness to seven hours in a single day.6Legal Information Institute. Federal Rules of Civil Procedure Rule 30 – Depositions by Oral Examination
Depositions are usually where dishonest plaintiffs trip. Keeping a fabricated story consistent across hours of detailed questioning is hard. Contradictions between deposition testimony and the complaint’s allegations are powerful ammunition. Experienced attorneys lock in details early in a deposition and come back later to force a plaintiff to pick which version is true.
Win Without a Trial on Summary Judgment
Once discovery wraps up, you may not need a trial at all. A motion for summary judgment wins if there’s no genuine dispute about any fact that matters and the law entitles you to judgment.7Legal Information Institute. Federal Rules of Civil Procedure Rule 56 – Summary Judgment In practice, that means showing the court the plaintiff can’t produce admissible evidence to support the claims they made in the complaint. If the plaintiff alleged a specific injury and discovery turned up nothing to back it, the court can end the case without the expense of a trial, treating unsupported facts as undisputed in your favor.
Summary judgment comes with its own anti-abuse rule. If the plaintiff submits affidavits or declarations in bad faith or purely to delay, the court can order them to pay your reasonable expenses and attorney’s fees, and may hold them in contempt.
Counterclaims for Malicious Prosecution and Abuse of Process
Defending the case is one path. Suing the plaintiff back is another. Two state-law theories apply when someone fabricates a lawsuit against you.
Malicious Prosecution
A malicious prosecution claim targets someone who brought a groundless case for an improper reason. Most jurisdictions require you to prove that the plaintiff initiated or continued the lawsuit, the case ended in your favor, no reasonable person would have believed there were grounds to bring it, the plaintiff’s primary motive was something other than winning on the merits, and you suffered actual harm. There is no federal cause of action for malicious prosecution; these claims live in state law.8Legal Information Institute. Malicious Prosecution
The timing catch matters: you generally can’t bring the claim until the original lawsuit has concluded in your favor. You have to win first, then sue. And winning isn’t enough on its own. You still have to show the case lacked any reasonable basis from the start, which is a higher bar than most people expect.
Abuse of Process
Abuse of process is related but different. Malicious prosecution asks whether the case should have been filed at all; abuse of process asks whether the plaintiff used a legitimate legal proceeding for an illegitimate purpose. The classic example is a lawsuit filed not to win a judgment but to pressure you into an unrelated business concession or to damage your reputation. You don’t have to show the case lacked probable cause, and you may be able to bring the claim before the underlying case ends.
When Lies in a Complaint Become Perjury
Most complaints don’t require the plaintiff to swear under oath that every allegation is true. But a “verified complaint” does: the plaintiff declares under penalty of perjury that the facts are accurate. Federal law allows written declarations under penalty of perjury to substitute for sworn statements in many contexts.9Office of the Law Revision Counsel. 28 USC 1746 – Unsworn Declarations Under Penalty of Perjury A plaintiff who signs a verified complaint and knowingly includes false statements of material fact has committed federal perjury, punishable by a fine, up to five years in prison, or both.
Perjury exposure grows as the case moves. Interrogatory answers are given under oath. Deposition testimony is given under oath. Affidavits supporting motions are sworn. A plaintiff who repeats the lies from the complaint under any of these forms has crossed from a civil problem into potential criminal liability. Prosecutors rarely act on complaint allegations alone, but a clear, provable lie under oath, surfaced in front of the judge, strengthens your position in the civil case whether or not criminal charges ever follow.